Luminaires typically include one or more light emitters accompanied by optional optical enhancements (reflectors, lenses, diffusers, etc.) to control the directionality and/or appearance of the light as it exits the luminaire. These light emitters and optional optics are typically housed in a luminaire housing that can take on a variety of different shapes, sizes, and other geometries.
Luminaires sometimes provide a bright area on the fixture from which light emanates, that can be in stark contrast to the lighting environment surrounding the luminaire. For example, an outdoor luminaire illuminated at night may provide a bright area that is in high contrast to the dark night sky. This contrast increases the glare perception of an observer.